About CalcBadger

CalcBadger is a collection of free online calculators built around one rule: show the work. Every tool states the formula it uses, names the standard or source the formula comes from, and walks through an example you can check by hand. If a calculation has competing conventions (tax years, building codes, test curves), the page says which one it follows.

Each calculator's math lives in a small, isolated function with unit tests whose expected values were worked out from authoritative sources (government tables, published standards, textbook formulas) rather than from the code itself. When a tool depends on data that changes annually, the page is dated and reviewed on that cycle.

Everything runs in your browser. There are no accounts, and nothing you type into a calculator is transmitted or stored; the numbers never leave the page.

The site is built and maintained by Owen Zhang. For corrections, suggestions, or anything else: [email protected]. Found a number that looks wrong? Please say so. Accuracy reports get fixed first.